I was disagreeing with "they shouldn't be".

I think we should care that our engineers have put the effort to understand the code they are responsible to produce. I don't care specifically about how they get that knowledge (I am using AI to learn myself, for example). But I disagree with the implicit assumption on the statement, which is, in my view, "humans don't need to understand the code any more" (because some fresh out of university might think they understand, but they really don't).